LA is not the only state where a strong challenger was lacking. Let's face it, Terrell, while a rightous person, was not the most energinzing candidate ever. You're right, all it would have taken was a stronger candidate. But in a state that hasn't elected a GOP senator since reconstruction, good Republican candidates are hard to find.
Also, while it is true the primary we had over 50% of the vote, that was when the GOP was pumped to get out there. Having won the Senate and the House and having heard relentlessly about the GOP sweep, it is likely that there wasn't much motivation to get out there. The job was done basically. Neither candidate turned them out. Move on an learn from the loss.
And finally, while I am Catholic, I am sick of hearing about how Catholics always vote abortion. There are more CINO (a great new term BTW) than real catholics. They are no longer the voting bloc they once were.